Battery packs that include a plurality of energy storage apparatuses housed in a pack case are known. The plurality of energy storage apparatuses each include one or more energy storage devices (battery cells) housed in an outer housing (module case). Each energy storage apparatus included in the battery pack requires a configuration in which electrical insulation of the battery cells is maintained and heat from the battery cells is prevented from transferring to surrounding components. For example, in Japanese Unexamined Patent Application Publication No, 2012-128983, when a plurality of the battery cells are to be housed in the module case, the plurality of battery cells are arranged spaced apart from each other in order to maintain electrical and heat insulation.
Another energy storage apparatus is known that can further secure electrical and heat insulation when a plurality of battery cells are to be housed in a module case by using partition plates formed between the plurality of battery cells in the module case.